Keros Therapeutics, Inc. — Director's Dealing 2021

May 13, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Keros Therapeutics, Inc. (KROS)
CIK: 0001664710
Period of Report: 2021-05-11

Reporting Person: Lachey Jennifer (Chief Scientific Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-05-11	Common Stock	M	2650	$0.30	Acquired	73837	Direct
2021-05-11	Common Stock	S	2650	$50.00	Disposed	71187	Direct
2021-05-13	Common Stock	M	6220	$0.11	Acquired	77407	Direct
2021-05-13	Common Stock	M	500	$0.30	Acquired	77907	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2021-05-11	Employee Stock Option (right to buy)	$0.30	M	2650	Disposed	2028-03-25	Common Stock (2650)	Direct
2021-05-13	Employee Stock Option (right to buy)	$0.11	M	6220	Disposed	2027-04-02	Common Stock (6220)	Direct
2021-05-13	Employee Stock Option (right to buy)	$0.30	M	500	Disposed	2028-03-25	Common Stock (500)	Direct

Footnotes

F1: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan.

F2: Immediately exercisable.

F3: One-twelfth (1/12th) of the shares subject to the option vested or shall vest in equal quarterly installments commencing on March 18, 2018, subject to the Reporting Person continuing to provide service through each such date.